Characteristics of Arc‑Induction Type DC Circuit Breaker Depending on Alteration of Induction Needle

Sang‑Yong Park,최효상 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.1

The existing DC (direct current) circuit breakers used for LVDC (low-voltage direct current) extinguish the arc by using an arc chute. The arc chute has an insulating inner barrier and cuts of the current by increasing the length of the arc and raising the arc voltage. If the arc chute fails to extinguish the arc energy by dissipating heat, the arc generation time will increase, thereby raising the possibility of damage to the cut-of contacts. Therefore, we proposed a new arc-induction type DC circuit breaker with key components like mechanical contacts, an induction needle, and a magnet. The arc generated between the contacts is guided to the induction needle and then grounded via a ground wire before being extinguished. The induction needle is a critical component of such mechanism because it induces the arc. The performance of the DC circuit breaker is determined by modifying the induction needle. In this study, the operational characteristics of the arc-induction type DC circuit breaker according to the variation of the induction needle was analyzed using the Maxwell program. The shape and position of the induction needle were changed, and the changes in the electric feld were compared via simulation. As a result, the electric feld value was confrmed to have been improved by up to about 20.5% when the two variables were applied

Interaction of <i>Veratrum nigrum</i> with <i>Panax ginseng</i> against Obesity: A Sang-ban Relationship

Park, Jinbong,Jeon, Yong-Deok,Kim, Hye-Lin,Lim, Hara,Jung, Yunu,Youn, Dong-Hyun,Jeong, Mi-Young,Kim, Hyun-Ju,Kim, Sung-Hoon,Kim, Su-Jin,Hong, Seung-Heon,Um, Jae-Young Hindawi Publishing Corporation 2013 Evidence-based Complementary and Alternative Medic Vol.2013 No.-

<P>Obesity has become a major health threat in developed countries. However, current medications for obesity are limited because of their adverse effects. Interest in natural products for the treatment of obesity is thus rapidly growing. Korean Medicine (KM) is characterized by the wide use of herbal formulas. However, the combination rule of herbal formulas in KM lacks experimental evidence. According to <I>Shennong's Classic of Materia Medica</I>, the earliest book of herbal medicine, <I>Veratrum nigrum</I> (VN) has antagonistic features against <I>Panax ginseng</I> (PG), and the PG-VN pair is strictly forbidden. In this study, we have shown the effects of PG, VN, and their combination on obesity in high-fat (HF) diet-induced obese mice and in 3T3-L1 cells. PG, VN, and PG-VN combination significantly reduced weight gain and the fat pad weight in HF diet-induced obese mice. They also significantly decreased lipid accumulation and the expressions of two major adipogenesis factors, PPAR<I><I>γ</I></I> and C/EBP<I><I>α</I></I>, in 3T3-L1 cells. In addition, the PG-VN combination had synergistic effects compared with the mixture of extracts of PG and VN on inhibition of PPAR<I><I>γ</I></I> and C/EBP<I><I>α</I></I> expressions at lower doses. These results indicate a new potential anti-obese pharmacotherapy and also provide scientific evidence supporting the usage of herbal combinations instead of mixtures in KM.</P>

Study on Microstructure and Mechanical Properties of the Al–25Cr–5Si (at%) Alloy Powder Using Gas-Atomization and SPS Process

Yong‑Ho Kim,Hyo‑Sang Yoo,Jeong‑Han Lee,Ik‑Hyun Oh,Hyun‑Kuk Park,Hyeon‑Taek Son 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7

In order to investigate the microstructure and mechanical properties on Al–25Cr–5Si (at%) alloy, a mixed powder with pureelements and an alloy powder using a gas atomization process were used. Fine and high purity Al–25Cr–5Si (at%) alloypowder was successfully prepared by gas atomization and densified using a spark plasma sintering (SPS) process. The overallpowder size distribution of the mixed Al, Cr, and Si elemental powders was in the range of 10–15 μm. The atomized Al–Cr–Sialloy powder was fine and spherical in morphology and difficult to be formed by intermetallic formation. Densification wasclearly confirmed at 1000 °C, with almost isolated pores formed, by clear removal of pores between particles, deformationof particles, an increase in the number of contacts, and a change in size between particles. As a result of XRD analysis ofthe sintered compacts, single phase was observed using the mixed powder, but the compact using gas atomization remainedthe alloy phase even at the process temperature. The Vickers hardness of the compacts by mixed powder was observed at59.70 Hv and the compact using gas atomized powders on the temperature 1000 °C of the Vickers hardness increased to702.6 Hv. The compressive yield strength of the compact with mixed powder was 195.24 MPa and the compressive strengthof the compact with gas atomized powder increased to 802.07 MPa. It is considered not to be decomposed by the AlCrSi,Al13Cr4Si4and Al8Cr5phases sintering process, resulting from the improvement of mechanical properties.

Analysis of Short-Term Prestress Losses in Post-tensioned Structures Using Smart Strands

Sang?Hyun Kim,Sung Yong Park,Sung Tae Kim,Se?Jin Jeon 한국콘크리트학회 2022 International Journal of Concrete Structures and M Vol.16 No.1

A Multi-Center Educational Research Regarding Breastfeeding for Pediatrics Residents in Korea

Yong Sung Choi,정성훈,김은선,Eun Sun Kim,Eunhee Lee,Euiseok Jung,So-Yeon Lee,이우령,Hye Sun Yoon,Yong Joo Kim,Ji Kyoung Park,Son Moon Shin,Ellen Ai-Rhan Kim 대한신생아학회 2022 Neonatal medicine Vol.29 No.1

Purpose: Pediatricians have a significant responsibility to educate mothers about the importance of breastfeeding. However, there have been minimal efforts in the courses of resident training in Korea. The purpose of this study is to evaluate the change in knowledge and attitude before and after a 4-week breastfeeding educational intervention among multicenter residents. Methods: Prospective interventional educational research was designed for residents at eight training hospitals in Korea. Institutional reviews were obtained in each hospital. The education curriculum consisted of 14 courses regarding breastfeeding theory and practice. These materials were used to teach pediatric residents for 4 weeks. Knowledge-based tests were administered before the course, and re-tests were administered after the course using different test items of similar levels. Test scores and survey responses were compared before and after the intervention. Results: A total of 73 residents (1st year 20, 2nd year 23, 3rd year 16, and 4th year residents 14) from eight training hospitals completed the intervention. Their average age was 30.3±2.9 years, 17 (23.3%) were male, 22 (30.1%) were married, and eight had more than one child of their own. The mean pre-test score was 61.8±13.4 and the mean post-test score was 78.3±7.5 (P<0.001). The inter-grade difference in the score was significant in the pre-test (P=0.005), but not significant in the post-test (P=0.155). There were more responses of obtaining confidence after the intervention (P<0.001). Conclusion: In our study, pediatric residents showed improvement in their knowledge and confidence level after 4 weeks of the breastfeeding curriculum. This will provide a basis for future policymaking in the training of pediatric residents regarding breastfeedReceived: 6 January 2022 Revised: 15 February 2022 Accepted: 15 February 2022 Correspondence to: Ellen Ai-Rhan Kim, MD Department of Pediatrics, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Korea Tel: +82-2-3010-3390 Fax: +82-2-3010-6978 E-mail: arkim@amc.seoul.kr A Multi-Center Educational Research Regarding Breastfeeding for Pediatrics Residents in Korea Yong-Sung Choi, MD,PhD1, Sung-Hoon Chung, MD, PhD2, Eun Sun Kim, MD, PhD3, Eun Hee Lee, MD4, Euiseok Jung, MD5, So Yeon Lee, MD, PhD5, Wooryoung Lee, MD6, Hye Sun Yoon, MD, PhD7, Yong Joo Kim, MD, PhD8, Ji Kyoung Park, MD, PhD9, Son Moon Shin, MD, PhD9, and Ellen Ai-Rhan Kim, MD, PhD5 1Department of Pediatrics, Kyung Hee University Hospital, Seoul, Korea 2Department of Pediatrics, Kyung Hee University Hospital at Gangdong, Seoul, Korea 3Department of Pediatrics, Kangwon National University Hospital, Chuncheon, Korea 4Department of Pediatrics, Korea University Anam Hospital, Seoul, Korea 5Department of Pediatrics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea 6Department of Pediatrics, Soonchunhyang University Seoul Hospital, Seoul, Korea 7Department of Pediatrics, Nowon Eulji Medical Center, Eulji University, Seoul, Korea 8Department of Pediatrics, Hanyang University Seoul Hospital, Seoul, Korea 9Department of Pediatrics, Inje University Busan Paik Hospital, Busan, Korea Neonatal Med 2022 February;29(1):28-35 https://doi.org/10.5385/nm.2022.29.1.28 pISSN 2287-9412 . eISSN 2287-9803 Copyright(c) 2022 By Korean Society of Neonatology This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http:// creativecommons.org/licenses/by-nc/4.0), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Original Article 29 Neonatal Med 2022 February;29(1):28-35 https://doi.org/10.5385/nm.2022.29.1.28 ing in Korea.

Earnings Management and CEO Turnover in Korean Credit Unions

Sang-Choon Park(박상춘),Wan Suk Ko(고완석),Yong-Sik Hong(홍용식) 한국국제회계학회 2018 국제회계연구 Vol.0 No.79

본 연구는 신용협동조합(신협)이 대손충당금설정액의 재량적 조정에 의하여 이익조정을 행하고 있는가를 실증적으로 검증하였다. 본 연구는 신협의 특유한 측면을 살펴 검증하였다. 먼저, 신용협동조합의 설립기반인 조합원의 특별한 관계, 즉 공동유대(지역․단체․직장)와 관련하여, 본 연구는 공동유대 유형에 따라 이익조정이 달라지는지 살펴보았다. 다음, 신용협동조합의 최고경영진 및 그 임기 횟수는 매 4년마다 조합원 직접선거에 의해 결정되므로, 이러한 선거가 이익조정 유인에 어떤 영향을 미치는지 검증하였다. 본 연구의 연구방법으로 금융회사의 이익조정관련 선행연구에서 많이 쓰이는 개별발생액접근법을 이용하였는데, 경영자의 재량성이 큰 기말대손충당금설정액(대손상각비)을 종속변수로, 비재량적이익을 주요 설명변수로 두고, 대손충당금을 조정하여 이익조정하는지 여부를 검증하였다. 분석을 위한 표본은 2015년 말 정상 영업 중인 지역조합 및 단체조합을 대상으로 2006년부터 2015년까지 10년 동안 7,445개 신협-연도 자료를 이용하였다. 실증분석 결과, 신용협동조합의 경영자들은 재량성이 큰 대손상각비를 이용하여 이익조정을 행하고 있음이 발견되었는데, 이사장은 초임기간(4년) 중 다음 선거를 의식하여 연임 기간(4년)에 비해, 그리고 초임기간 중 마지막 연도는 초임 또는 연임기간의 다른 연도에 비해, 이익조정을 더 크게 하는 것으로 검증되었다. 그리고 지역조합이 단체조합보다 이익조정을 더 활발하게 행하는 것으로 나타났다. 위와 같은 신협 경영자의 이익조정의 증거를 바탕으로, 본 연구는 다음의 시사점을 제공하고 있다. 금융당국은 경영자의 이익조정 재량권을 축소하기 위해 자산건전성 분류기준 및 회수예상가액 산정기준을 보다 명확하고 객관화하여 개선하여야 한다. 아울러 조합의 규모나 공동유대 특성 등을 고려한 차등 감독도 시행할 필요가 있다. This study empirically tests whether and how CEOs of credit unions manage their reported earnings through management of allowance for bad debts (ABD) by examining distinct features of credit unions. With regard to the common ties of their members on which the unions are established, it tests whether credit unions’ earnings management differs by type of establishment ties. Then, because the CEOs of unions and their number of terms of office are determined by the direct election by their members, the study examines how earnings management is affected by the existence of the election. The study uses a specific accruals approach widely used in the literature on earnings management of financial companies. It uses bad debt expense (BDE), a major discretionary item, as the dependent variable and non-discretionary earnings as a primary explanatory variable to test the hypotheses. The sample comprises 7,445 Korean credit union firm-years spanning 2006 to 2015. The empirical results revealed that credit unions manage their reported earnings by using BDE, especially more in the first office term of their CEOs than in the consecutive term, and in the last year of the first term, and that earnings were more actively managed in regional unions than in association ones. This study provides policy implications. Financial supervisory authorities should improve the objectivity and clarity of asset soundness criteria, and provide better and objective estimation methods for expected loan recovery so as to minimize CEOs’ discretion in earnings management. They should also provide differential supervision for credit unions depending on their types of common ties and size.

연구논문 : 도심 친수공간 적지선정을 위한 평가기준의 가중치 산정방법 개발

김성만 ( Sung Man Kim ),이재춘 ( Jae Choon Lee ),박민정 ( Min Jung Park ),권재범 ( Jai Bum Kwon ),이용운 ( Yong Woon Lee ) 한국환경영향평가학회 2012 환경영향평가 Vol.21 No.5

The urban waterfront well created, could provide mental stability and comfort and also foster personality. In addition it could provide the calmness and rest of mind. Especially, recently the urban waterfronts are restored here and there and are created whenever developing a new town The purpose of this study is to develop a method of calculating the weight of each evaluation criterion for deciding the priority of restoration among for deciding the priority of restoration among the urban waterfronts. The method includes the analytic hierarchy process that can calculate the reasonable weight of each evaluation criterion, because the importance (weights) of evaluation criteria appears to be different among the evaluators; the results of this study can be summarized as that this method can be useful for calculating the weights of evaluation criteria, and also that the superiority of ecological resources is the most important factor (highest weight) in selecting the best waterfront, followed by accessibility, tourism vacation, and proximity to parks. And then the lowest factor in importance is the scale of reservoir.

계룡산국립공원의 나비류 군집에 관한 연구

전성재 ( Sung Jae Jeon ),조영호 ( Young Ho Cho ),한용구 ( Yong Gu Han ),김영진 ( Young Jin Kim ),최민주 ( Min Joo Choi ),박영준 ( Young Jun Park ),남상호 ( Sang Ho Nam ) 한국환경생태학회 2012 한국환경생태학회지 Vol.26 No.3

고도의 변화는 종 다양성 및 풍부도 그리고 생물 종 구성에 있어 매우 중요한 역할을 하는 요인으로 최근에는 나비를 비롯하여 곤충의 고도에 따른 분포 형태에 관하여 많은 관심이 집중되고 있다. 본 논문에서는 계룡산국립공원의 고도에 따른 나비분포를 조사하여, 종 보전 및 효율적인 관리방안을 제시하고자 하였다. 본 연구에서는 고도가 증가함에 따라 종과 개체수가 감소하는 경향이 나타났으며, 이는 수관울폐로 인한 그늘의 증가가 원인일 것으로 사료된다. 고도의 영향 이외에도 종의 분포에 영향을 주는 요인을 분석한 결과, 경사도 및 식생군락 그리고 수계거리가 종의 분포 변화와 상관관계가 있는 것으로 조사되었다. 이러한 종들은 먹이식물과 밀접한 관련이 있으므로 추후에 숲 내부의 변화를 감지하는데 적합한 생물지표종을 선정한다면 시간과 비용을 감소시킬 수 있을 뿐만 아니라 효율적인 생물다양성 평가를 내릴 수 있을 것으로 판단된다. 또한 추후에 기후 및 미기후, 그리고 먹이식물과 같은 환경요인들의 자료를 축적하고 정량화 할 경우 나비 분포를 예측할 수 있어 종 보전에 있어 더 효율적이라고 사료된다. Altitude is a factor that plays an important role in the diversity, richness and composition of species. Recently, much attention has been paid to the distribution of butterflies and insects according to altitude. The purpose of this article is to propose a method to preserve and manage species efficiently by reviewing the distribution of butterflies according to different altitudes in Mt. Gyeryong National Park. This study found that the number of species and individuals decreased as the altitude increased, possibly due to the increased amount of shade caused by the crown density. When analyzing the factors influencing the distribution of species other than altitude, it was found that the slope, vegetative colonies and hydrosphere distance were correlated with the change in species distribution. As these species are closely related to food plants, it may save time and reduce the cost as well as allow an efficient evaluation of the bio-diversity if these species are selected as biological indicator species suitable for detecting the changes in the forest. It is judged to be a more efficient means of species preservation to accumulate and quantify the materials regarding environmental elements such as the climate, microclimate and food plants, as this would allow the butterfly distribution to be estimated.

아파트경매에서 낙찰가율의 결정요인에 대한 연구

조상용(Cho, Sang-Yong),박승록(Park, Seung-Rok) 한국주거환경학회 2015 주거환경(한국주거환경학회논문집) Vol.13 No.4

In this paper, we study the highest bid price determination mechanism of the court auction markets for apartments that are under distraint because of the insolvency of the owner of the apartments. In addition to the typical variables used in previous literatures on the determination of highest bid price, we add the variables that represent the characteristics of the tenants categorized by the priority order of the tenants’ deposits in the distribution process of the money obtained from the auction of the apartments. Unlike our general perception, the results show that the presence of pretense tenants on the priority list of the distribution of dividend from the auction hardly affects the determination of the highest bid price. In addition, the presence of legal counter power of tenants against the landlord does not affect the highest bid price, either. The first policy implication of this paper is that to set up a fair institutional mechanism in court auction market for apartments under distraint, the auction court needs to ask the applicant of the auction to prove whether the listed tenants are true to eliminate the pretense tenants. The second policy implication is that the court needs to disapprove the seniority of the pretense tenants’ claim on the distribution of dividends from auction of the apartments.

지방공무원의 행정개혁에 대한 수용성과 그 영향요인

정주용 ( Ju-yong Jung ),박성식 ( Sung-sik Park ) 명지대학교 정부행정연구센터 2015 정부행정 Vol.11 No.-

이 연구는 박근혜 정부가 추진 중에 있는 행정개혁인 정부3.0에 대한 지방공무원들의 수용성을 연구하였다. 행정개혁은 그 집행주체인 일선 공무원들의 반응을 통해 구체화될 수 있기 때문에 일선공무원들의 행정개혁에 대한 수용성은 개혁결과에 상당한 영향을 미칠 수 있기 때문이다. 분석결과, 지방공무원들은 정부3.0을 통한 기대효과들 중 국민과 소통하는 정부, 관료적인 행정서비스 개선, 수요자 중심의 행정, 투명한 정부, 정부부문의 혁신 등에 대한 기대감이 클수록 수용성이 높아짐을 알수 있었다. 또한 정부3.0의 방향성에 대해서는 국가정보 인프라 강화, 혁신적인 조직문화의 조성, 정보공개의 확대 등에 초점을 맞추어야한다는 응답이 높을수록 수용성이 높은 것으로 나타났다. This paper tries to find out local government officers’ Acceptance on Administrative Reform that President Park’s central government is pursuing. Their acceptance may have major impact on the results of the administrative reform since the reform could be formalized by the response expressed by local government officers. According to an empirical research results, it was proven that the more such expectations get bigger as government’s communication to citizens, the improvement of bureaucratic services, citizen- focused administration, clean-minded culture and reform on government divisions, the bigger the acceptance were made by local government officers. In addition, they also mentioned the administrative reform should be directed to reinforce national IT infrastructure, to construct an innovative organization culture, to expand the release of information and so on.